MLA

Sanborn Map Company, issuing body. Insurance Maps of Greenwich, Fairfield County, Connecticut. 1906. https://collections.library.yale.edu/catalog/11128862.

APA, 6th edition

Sanborn Map Company, issuing body. (1906). Insurance Maps of Greenwich, Fairfield County, Connecticut. [Atlases--Connecticut--Greenwich (Town)--1906.--local, Cadastral maps--Connecticut--Greenwich (Town)--1906.--local]. https://collections.library.yale.edu/catalog/11128862.